Method of amalgamating metals.



' No. 707,97l. Y Patented Aug. 26, |902.

P. A. KNAPPE. y f METHOD 0F AMALGAMATING METALS.

(Application led Mar. 8, 1902)' (No Model.)

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UNITED STATES PATENT OFFICE.

PAUL A. KNAPPE, OF GRAN'IVILLE GEORGIA, ASSIGNOR, BY MESNE ASSIGNMENTS,TO AMERICAN AMALGAMATING COMPANY, A OOR- PORATION OF GEORGIA.

M ETHOD OF AMALGAMATING v METALS.

SPECIFICATION forming part of Letters Patent No. 707,971, dated. August26, 1902.

' Application filed March 8, 1902. Serial No. 97,231. (No specimens.)

To a/ZZ whom t may concern.-

Be it known that I, PAUL A. KNAPPE, a citizen of the United States,residing at Grantville, in the county of Coweta and-State of Georgia,have invented an Improvement in Methods of Amalgamating Metals, of whichthe following description, in connection with the accompanying drawings,is a specication, like letters on the drawings representing like parts.

My invention relates to the amalgamation of metals by methods whereinseparation of the metal is effected by intermingling a mixture ofcomminuted ore and water with a quantity of free mercury, and hasparticular reference to ores carrying large proportions of sulfids andwhere the precious metal is combined with refractory materials. A verythorough intermingling of the mercury and ore is obviously requisite toobtain satisfactory results by this method. A thorough mixing, however,is usually accompanied by a loss of a considerable percentage ofthe'mercu ry and amalgam, which passes off in small particles with thetailings or gangue. It is also very difficult to prevent the loss ofmany iine particles of met-al with the gangue,lparticu` larly whenthe-ore has been ground to a high degree of fmeness', without subjectingthe same to repeated intermixtu re with mercury.

The object of my invention is to provide a simple process ofamalgamation which shall permit the attainment of a high commercialefficiency. A

My improved method will be best understood by reference to a specificmeans for carrying it into effect, while its scope will be particularlypointed out in the appended claims.

Referring to the accompanying drawings, Figure l is a side elevation,partly in section, of an apparatus adapted to carry out my improvedmethod, showing the general relation of theY parts. Fig. 2 is a brokencentral sectional view of 'the amalgamating-chamber with its att-achedparts, and Fig. 3 is a crosssectional view of the amalgamator-chamber onthe line 3 3 of Fig. 2.

A is an amalgamator-tube suitably supported in a horizontal position andpreferably formed, as shown, with anged ends. The tube is closed at itsends by heads B B', bolted to anges, and providing glands C C for thestuffing-boxes D D', forming therewith bearings for the shaft E. Aninlet-pipe a enters the initial end of the cylinder, preferably at thetop, and an outlet or discharge pipe b is provided at the outlet endthereof, likewise located, preferably, near the top. A shield orbaffle-plate c,which may be formed of metal or other suitable material,is removably fitted into grooves in the wall of the cylinder A,immediately beneath the said inlet-pipe. A series of radial mixing-armsd is carried by the shaft E throughout the length of the tube A, exceptwhere they would conflict with the shield c. These are screwed orotherwise suitably attached to the shaft E and are adapted to berevolved wit-hin the chamber A with but slight clearance. These areshown in staggered sets of two and are suitably dimensioned and disposedwith relation to the space in the chamber A to cause thoroughinterminglingof the mercury and the pulp.

As a convenient means for draining the amalgamator, but forming noessential feature-thereof, I have shown a trough-like depression cformed in the under wall of the tube and increasing in depth toward thelatter end thereof. This is best shown by Fig. 2 and the cross-sectionin Fig. 4. At the outlet end of the tube and near the deepest part ofthe depression is cast a boss, into which isV screwed the plug f,carrying the drain-pipe g, controlled by a valve, through which themercury Vmay be removed at suitable` intervals.

A source hof electric current is shown suitably connected with theinterior of the chamber A, preferably through insulating-plugs, to causethe passage of a current through the contents thereof.

O is an initial ore-receptacle adapted to feed the ore to the first of aseries of sizers F F F,

having successively lower levels. kThese sizes are shown suitablylocatedto drain into the inlet of the amalgamator throughpipes i c' 't'at a point elevated above the outlet thereof to cause a steady progressof the pulp therethrough under the pressure of the superimposed pulp inthe inlet-pipe. The amount of flow through these pipes may be regulatedby valves j j j. Overflow-pipes 71: 7c 7c are provided for the sizers tocarry the waste from one .to the other and thus throughout the series,the overflow-pipe from the last sizerleading to a blanket-sluice,typified at Z in the drawings. The discharge-pipe of the amalgamatorleads to a second series of similar sizers F' F F, provided with similaroverflow-pipes It 7d 7a and drain-pipes t" t" t", the latter beingprovided with valves j j' j and draw-od cocks p p p and leading to thereturn-pipe m. The overflow from the last sizer leads to another similarblanket-sluice l', the end only of which is shown in the drawings. Anelevated water-tank G or other suitable source distributes water to thesizers through the main feed-pipe H, Which is shown with dependingvalve-controlled branches n n n, extending downward into the individualsizertanks of both sets. The ends of these branch pipes are preferablyprovided with perforated tips o o o. An inclined return-pipe m leadsfrom the last sizer F to the bucket elevator or conveying means I, bywhich the returned materials lnay be elevated to the initialorereceptacle C. This elevator is conveniently driven through the shaftK, the belt L, and driving-pulley N on the shaft E, power being suppliedto the latter from any suitable source through the pulley N.

My improved method is carried out by the described apparatus in thefollowing manner: The ore is conveyed by any suitable means to theinitial receptacle C. I'Iere it is joined, as will afterward appear, bythe discharge from the bucket elevator, and the mixture passes into thefirst sizer F. The water-jets from the pipes n serve to agitate anddilute the mass, so that the heavier particles gravitate to the bottomof the sizer and are conveyed by the pipe i to the inlet-hopper of theamalgamator. The lighter particles pass off at the overflow and aresubject to a second settling or concentrating process in the secondsizer. From here the overflow may be carried to a third sizer, and soon, as many sizers being employed as may be found desirable to extractall the concentrated portions of the ore. As a means for securing suchconcentrates as escape from the last sizer I preferably cause theoverflow therefrom to pass over the blanket-sluice Z. This blanket maybe taken up and washed to remove the mineral held by it as often ascircumstances may demand. It is evident that any means which will afforda suitable concentration of the mixture and a separation of the lighterparticles therefrom may be employed in place of the specific means Ihave shown. To any device equivalent or similar to the series of sizersshown I have applied the generic term of concentratoin The concentratedore or pulp is passed to the amalgamator through the inlet-pipe a and onentering the chamber is prevented from coming into immediate contactwith the mercury and flouring the latter by the shield c. While conveyedthrough the amalgamator under the pressure of the superimposed pulp itis subject to the steady action of the miXing-arms,which enforce athorough intermingling of the mercury and the pulp and an amalgamationof the met-al carried thereby. The lighter gangue or tailings whichescapes from the amalgamating-chambers through the pipe h carries withit numerous small globules of mercury and amalgam as well as particlesof unamalgamated precious metal. For the separation of these substancesI pass the tailings through a second concentrator, (represented by theseries of sizers F F F.) In construction and function this concentratoris similar to that already described. The heavier particles of mercuryand amalgam and the finer particles of precious metal, as well as theconcentrates or bits of refractory metal unsusceptible to amalgamation,gravitate to the bottoms of the several sizers. These tend to passthrough the pipes i' 1l t" to the return-pipe m, by which they aredelivered to the bucket elevator, the latter conveying them to theinitial ore-receptacle C. By adjusting the valves jjj this flow may beregulated, if desired, to include only the comparatively fine particlesof mercury, amalgam, and metal, leaving the coarser concentrates to bewithdrawn from the sizers through the draw-off cocks p p p at suitableintervals. The bucket elevator or conveyer may be constantlyoperated andwith the sizers and circulating-pipes described affords acontinually-repeated circulation of the unamalgamated metals through theamalgamator until they undergo the desired amalgamation. It also permitsthe recovery and restoration to the amalgamator-chamber of all freeparticles of mercury and amalgam carried off in the gangue. As a meansto sustain the activity of the mercury and prevent its sickening .I havefound it advantageous to employ a source of electricity suit-ablyconnected with the interior of the amalgamating-chamber to cause apassage ot` the electric current through the contents thereof. This maybe accomplished as indicated; butIam not limited to any particulararrangement in this respect. In practice I have found an alternatingcurrent or one subject to repeated reversals highly efficacious, and inthe drawings I have conventionally shown an alterhating-current source,although I am not limited to any particular kind of current for thispurpose.

The form of amalgamator-tube described I have found particularlyefficient in practice for causing a thorough intermingling of the pulpand the mercury without danger of flouring the latter. Any known meansmay be substituted therefor. I have also found it advantageous to causethe pulp to pass through the amalgamator under pres- IIO sure, and theelevated position of the metal ore-receptacle, sizers, and feed-hopperis merely selected as a simple and practical means of aording therequisite pressure in the amalgamatorlfor this purpose. It is notnecessary that this construction should be followed or that anyparticular 'means for obtaining pressure should be employed, nor is myinvention to be restricted to the ein ployment of any pressure in thisconnection. The bucket elevator is merely shown as illustrative of anypractical means for conveying the concentrates to a point Where they maybe returned to the amalgama'tor-chamber.

The structure shown and described is submitted for illustrative purposesonlyand as well adapted in practice to carry out my method. My inventionis not limited, however, to the specific means shown for carrying outany or all of the steps, which may be performed in any known Way.

IY claim- 1. The method of amalgamating metals which consists in causingpulp to traverse an amalgamating-space containing mercury, forciblyintermingling the mercury and the pulp during its passage therethrough,removing the gangue from said space, separating the heavier particlesfrom said gangue, and causing them to retraverse the amalgamatingspace.

2. The method of amalgamating metals which consists in forming a pulp,forcibly intermingling the same lWith mercury, removing the ganguetherefrom, separating the heavier particles from said gangue, andconducting` the heavier particles thus separated to the ingoing pulp.

- 3. The method of amalgamating metals which consists in forming a pulp,forcibly intermingling the same with mercury, removing the gan guetherefrom, separating the heavier particles from said gangue, conductingthe particles thus separated to the ingoing pulp and concentrating thepulp and heavier particles before entrance into the amalgamator.

4. The method of amalgamating metals which consists in causing a pulp totraverse a restricted amalgamating-space containing mercury, forciblyintermingling the mercury and the pulp duringits passage therethrough,removing the gangue from said space, separating the heavier particlesfrom said gan gue and causing them to retraverse the amalgamating-space.

5. The method of amalgamating metals which consists in separating theheavier metallic particles from the gangue and causing their repeatedpassage again through the amalgamating-space and their repeated enforcedintermingling With the mercury therein until amalgamation is effected.

6. The method of conducting 'the amalgamation of metals which consistsin separating the heavier particles from the gangue, causing arepeatedcirculation of the same through the amalgamating-space and an enforcedintermingling with the mercuryuntil amalgamation is effected,andwithdrawing from such circulation those particles unsusceptible toamalgamation.

7. The method of conducting a continuous amalgamation of metals whichconsists in causing the passage of pulp through a coniinedmercury-containing space, forcibly intermingling the mercury and pulp byagitation of the same, removing the gangue from said space, extractingthe lheavier particles from said gangue, causing said heavier particlesto be returned again into the mercurycontaining space, and subjectingthem to reintermingling With the mercury therein.

8. The method of amalgamating metals which consists in causing apulp totraverse underpressure an amalgamating-space containing mercury,forcibly intermingling the mercury and the pulp during its passagetherethrough, removing the gangue from said space, separating theheavier particles from said gangue and causing them to retraverse theamalgamating-space.

9. The method of amalgamating metals which consists in forming a pulp,causing a passage of said pulp under pressure through amercury-receptacle, forcibly intermingling 'the mercury and pulp duringsuch passage,

removing the gangue from said receptacle, separating the heavierparticles from said gangue, and conducting the heavier particlesv thusseparated tothe ingoing pulp.

10. The method of amalgamating metals which consists in forming a pulp,causing the passage of said pulp through amercury-receptacle, forciblyintermingling the mercury and pulp during such passage, removing thegangue from said receptacle, separating the heavier particles from saidgangue, conducting the particles thus separated to the ingoing pulp, andconcentrating the pulp and heavier particles before entrance into theamalgamator.

11. The method of amalgamating metals which consists in causing a pulpto traverse an amalgamating-space containing mercury, forciblyintermingling the mercury and pulp during its passage therethrough,removing the gangue from saidspace, separating the heavier particlesfrom said gangue, causing them to retraverse the amalgamating-space andmaintaining the activity of the mercury by an alternating current.

12. The method of amalgamating metals which consists in forming a pulp,causing the passage of the same through a mercury-receptacle, forciblyintermingling the mercury and the pulp, removing the gangue therefrom,extracting the hea-vier particles from said gangue, returning saidheavier particles to the mercury-receptacle, and maintaining theactivity of the mercury by an electric current.

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13. The method of amalgamating metals which consists in forming a pulp,conducting the same into a mercury-receptacle from a position elevatedthereabove, causing the circulation of said pulp through said receptacleby the pressure of the superimposed pulp, interminglingr the mercury andpulp, removing the gangue from said receptacle, extracting the heavierparticles from said gangue, conveying said heavier particles to theingoing pulp.

In testimony Whereo:` I have signed my name to this specification in thepresence of xo two subscribing witnesses.

PAUL A.y KNAPPE.

Witnesses:

THOMAS B. BOOTH, EVERETT S. EMERY.

